My 02 X5 3.0 is having the all to common issue with its Transfer Case/Drive shaft slipping. Reading all the posts on this topic and a a brief discussion with a BMW mechanic, I've learned the front drive shaft design is flawed because it barely engages into the transfer case. The common result is stripping of the splines and the need to replace both shaft and transfer case. Big bucks! I hope to repair this only once. Does anyone know of an after market source for a longer drive shaft?

My understanding is that having mismatched tires front/rear, or driving with significantly different tire pressures front/rear, both of which cause a relative difference in tire rotations, is what stresses the splines and causes the damage you have. There are lots of X5s that have never had front driveline issues.

Check on bimmerboard and roadfly, I seem to recall people complaining about it and they found someone (company) that made longer ones, in Texas maybe?

Quote:

Originally Posted by heybernbb

My 02 X5 3.0 is having the all to common issue with its Transfer Case/Drive shaft slipping. Reading all the posts on this topic and a a brief discussion with a BMW mechanic, I've learned the front drive shaft design is flawed because it barely engages into the transfer case. The common result is stripping of the splines and the need to replace both shaft and transfer case. Big bucks! I hope to repair this only once. Does anyone know of an after market source for a longer drive shaft?

i read a thread here a couple of weeks ago
i thought i had saved it on my pc but can`t locate it right now
if you search then you will see pics of the guy cutting the splined end from propshaft then he flips it to get good splines to enter transfer case
i think he also needed to weld in a spacer so as the splined shaft could contact good splines in output shaft.
propshaft needs to be balanced once repaired

I'm hoping to be able to help you out, I'm getting close to having the redesigned parts to repair the front shafts on an exchange basis. As in the other post it will save you the cost of the transfercase although you will still have to remove/slide back the case to install the new shaft because of the new longer splines. I'm expecting to hear from the engineer any day on when I'll get the new splines. I've been having trouble getting the splines cut because they are not a standard size. I will post as soon as they are available. Thanks to joe v for being so patient, and would the guy from Pa. please call or pm me your number, my phone didnt save it for some reason. Also, if this takes off, I'd like to talk about sponsoring the site. Thanks, Tom Gottschalk 262-749-0689.

My understanding is that having mismatched tires front/rear, or driving with significantly different tire pressures front/rear, both of which cause a relative difference in tire rotations, is what stresses the splines and causes the damage you have. There are lots of X5s that have never had front driveline issues.

Judging by the damaged ones I've seen so far it appears to be caused by the seal failing and moisture getting into the splines and then rust forms and slowly grinds away at the splines. I don't think the minimal tire size difference would cause that, only because the front and rear outputs of the case are not locked together. When the splines give out, the vehicle is rendered immobile, the rear will not drive without the front, so there must be some slippage in there to compensate. I do believe it would mess with traction control because I checked the air in ours and the fronts were lower than I'd like to admit, and after re-inflation, the trac control and abs light kept randomly coming on for about a week, then just stopped.